Disconnect arrangement for multi-unit printing press

ABSTRACT

A disconnect arrangement for a multi-unit sheet feed press in which the transfer cylinder gear is shifted axially out of mesh with the gears on the adjacent cylinders thereby interrupting the press drive train and permitting individual operation of the units. Means are provided to prevent disengagement of the cylinder in one rotational position and to maintain the cylinder in a predetermined position after it has been disconnected. Interrupted portions on the transfer cylinder are angularly spaced such that, upon disconnect, these portions are facing the adjacent cylinders and provide a space into which the grippers on the adjacent cylinders can open as the units are individually rotated. Means are also provided to assure that, upon reengagement, the gears are brought into mesh in exactly the same position they occupied when disconnected.

United States Patent Southam et al.

[54] DISCONNECT ARRANGEMENT FOR MULTI-UNIT PRINTING PRESS [72] Inventors: Donald L. Southam, Brecksville;

Thomas J. Kacmarcik, Parma Heights, both of Ohio [73] Assignee: Harris-Intertype Corporation,

Cleveland, Ohio [22] Filed: April 2, 1971 211 Appl. No.: 130,708

[52] US. Cl ..101/183, 101/426 [51] Int. Cl. ..B41f 7/06 [58] Field of Search ..lO1/l36, 137, 138-140,

lO1/141l45,152,153,154,174,l83,184, 216-218, 246, 232, 411, 426

[56] References Cited UNITED STATES PATENTS 2,707,914 5/1955 Harrold ..lO1/183 3,221,651 12/1965 Tagliasacchi 101/183 5] Oct. 24, 1972 3,516,355 6/1970 Giuiuzza ..101/183 Primary Examiner-J. Reed Fisher Attorney-Yount and Tarolli [57] ABSTRACT A disconnect arrangement for a multi-unit sheet feed press in which the transfer cylinder gear is shifted axially out of mesh with thegears on the adjacent cylinders thereby interrupting the press drive train and permitting individual operation of the units. Means are provided to prevent disengagement of the cylinder in one rotational position and to maintain the cylinder in a predetermined position after it has been disconnected. Interrupted portions on the transfer cylinder are angularly spaced such that, upon disconnect, these portions are facing the adjacent cylinders and provide a space into which the grippers on the adjacent cylinders can open as the units are individually rotated. Means are also provided to assure that, upon re-engagement, the gears are brought into mesh in exactly the same position they occupied when disconnected.

23 Claims, 13 Drawing Figures DISCONNECT ARRANGEMENT FOR MULTI-UNIT PRINTING PRESS This invention relates to a multi-unit sheet fed rotary printing press and, more particularly, to a disconnect arrangement in which a transfer cylinder is disconnected from the cylinders on opposite sides thereof to permit individual rotation of the press units without interference between the interdigitated gripper fingers associated with the disconnected transfer cylinder and the adjacent cylinders.

Although the invention will be described with particular reference to a multi-unit three cylinder offset sheet fed press in which a plurality of transfer cylinders are used to transfer a sheet from one unit to the next, it will be appreciated that the invention may be used with any press in which it is desired to disconnect an intergeared cylinder from adjacent cylinders having interdigitated fingers.

ln multi-unit sheet fed presses, various transfer mechanisms are provided to transfer the sheets from one printing unit to the next. Typically, these transfer mechanisms comprise rotating transfer cylinders which are intergeared with the press units. In one conventional arrangement, three transfer cylinders are used with each of the two outer cylinders being associated with the impression cylinders of two adjacent printing units and the third cylinder being located between the two outer cylinders and transferring the sheet from one outer transfer cylinder to the other. Gripper fingers both on the impression cylinders and the transfer cylinders grip and release the sheets in a closely timed sequence whereby the sheet is carried around one cylinder and transferred to the next. These gripper fingers are normally positioned in a gap formed in the sur faces of the cylinder and are moved radially outward above the surface of the cylinder in a timed sequence controlled by a cam and follower mechanism.

When a sheet is being transferred from one cylinder to the next, the fingers on the two cylinders are interdigitated so that the gripper fingers on one cylinder move outwardly into the gap of the adjacent cylinder to release the edge of the sheet while the gripper fingers on the other cylinder, which have been opened, close on the edge of the sheet. The movement of the fingers as they open and close must be timed with relation to the rotation of the cylinders so that the gaps on adjacent cylinders coincide to accommodate the radial movement of the grippers during the sheet transfer.

In multi-unit printing presses of this type, it frequently is necessary or desirable to perform certain make-ready or clean-up operations on the individual units of the press. However, since all of the units in a multi-unit printing press, including the transfer cylinders, normally are geared together, it is necessary that some means be provided for disconnecting one unit from the other so that the disconnected unit can be operated independently for the make-ready or clean-up operation. To this end, it has been suggested to disconnect individual printing units from the press gear train and provide auxiliary motors whereby each disconnected unit can be individually rotated. However, it will be appreciated that when one unit is disconnected from the next, the timed relationship between adjacent cylinders, one rotating and the other stationary, no longer prevails and there is a possibility that the grippers on the cylinder being rotated will interfere with or engage the periphery of the disconnected adjacent cylinder. Moreover, when reconnecting the unit it is important that they be reconnected in the proper timed relationship to avoid gripper interference when the units are operated simultaneously.

To assure the proper re-timing of units, the prior art has utilized various techniques such as timing gears, one-toothed clutches or pins in the main drive to provide for the reconnection of the units in their proper angular relationship. However, as a result of such arrangements, these pins and one-toothed clutches have had to carry driving forces for the units during normal printing. It is preferable that drives for the printing units be through gear teeth during the normal printing operation.

It is a principal object of this invention to provide a disconnect arrangement for a multi-unit printing press which obviates the need for pins, one-tooth clutches or timing gears and which assures that the drive for the press is solely through meshing gear teeth during normal printing operation.

Another primary object of this invention is to provide a disconnect arrangement in which a transfer cylinder of a multi-unit press may be disconnected from the press drive gear train thereby to permit individual operation of the press units while maintaining the disconnected transfer cylinder in a predetermined angular position such that the grippers on adjacent rotating cylinders do not interfere with the disconnected cylinder.

It is another important object of this invention to provide a disconnect arrangement for a multi-unit printing press in which the units are disconnected by displacing one of the gears in the gear train out of meshing engagement with the adjacent gears and which includes means preventing re-engagement of the gears except in a predetermined angular relationship.

More specifically, this invention contemplates a disconnect arrangement for a multi-unit sheet fed printing press in which a sheet transfer cylinder is intergeared with a pair of other cylinders on opposite sides thereof with each of the cylinders having sets of interdigitated gripping fingers thereon for successively transferring sheets from one cylinder to the next. The transfer cylinder has interrupted portions in its periphery and the adjacent pair of cylinders are angularly spaced about the axis of the transfer cylinder such that a pair of these interrupted portions may be sim ultaneously adjacent the cylinders on opposite sides thereof. The disconnect arrangement includes means for disconnecting the transfer cylinder from the gear train with means for locking the disconnected transfer cylinder against rotation in a predetermined angular relationship relative to the adjacent cylinders whereby the interrupted portions on the transfer cylinder periphery face the adjacent cylinders so that, upon rotation of the adjacent cylinders, the grippers thereon open into the space provided by the interrupted portions.

In the preferred form of the invention, the transfer cylinder is disconnected from the press drive train and the adjacent cylinders by shifting the entire transfer cylinder axially thereby shifting its associated gear out of meshing engagement with the gears of the adjacent cylinders.

An important aspect of the preferred form of the invention resides in the provision of keeper members on each of the gears of the adjacent cylinders with each of the keeper members having a circular periphery which interferes with the teeth of the mating gears and which extend around all but a small portion of their gears. The keeper members cooperate with the transfer cylinder gear to prevent engagement or disengagement of the gear of the transfer cylinder except in only one posi tion. In all other positions, the keeper members prevent axial movement of the transfer cylinder gear.

The keeper members and the transfer cylinder gear include means which are operative to prevent re-engagement of the gear teeth in the event they are out of alignment one-half gear tooth width, together with means for camming the gear teeth into exact alignment if the gears are aligned within one-half gear tooth width.

Other objects, features and aspects of the invention will be more apparent upon a complete reading of the is positioned between the impression cylinders of the two units 12,14 and transfers the sheets from the impression cylinder of the first unit to the second unit. A second transfer unit comprising three transfer cylinders 30, 32, 34 is operative to transfer the sheets from the impression cylinder of the second unit 14 to the impression cylinder of the third unit 16, while another transfer cylinder 36 transfers the sheets between the impression cylinders of the third and fourth units.

Each of the transfer cylinders has a circumference which is the same as or an equal multiple of a cylinder circumference required to print a single sheet. As

' shown, the transfer cylinders are double size, that is,

following description which, together with the attached drawings, discloses but a preferred form of the invention.

Referring now to the drawings wherein like reference numerals indicate like parts in the various views:

FIG. 1 is a schematic illustration in side elevation of a typical multi-unit press in which the principles of this invention may be used;

FIG. 2 is a sectional view along line 2-2 of FIG. 1;

FIG. 2A is an enlarged view, partly in section, of one of the gripper cam followers;

FIG. 3 is a sectional view along line 33 of FIG. 2;

FIG. 4 is a sectional view along line 4-4 of FIG. 2;

FIG. 5 is an elevational view of one of the keeper rings;

FIG. 6 is a view along line 6-6 of FIG. 5;

FIG. 7 is a fragmentary view illustrating the meshing engagement of the keeper ring with the transfer cylinder gear,

FIG. 8 is a view similar to FIG. 7 and shows the mesh of the gears and the position of the keeper rings;

FIG. 9 illustrates the position of the gear teeth and the keeper ring when the gears are out of rotational alignment by one gear tooth;

FIG. 10 is a view similar to FIG. 9 but shows the gears out of rotational alignment by less than one-half gear tooth;

FIG. 11 is a schematic hydraulic circuit which may be used with the disconnect arrangement;

FIG. 12 is a schematic illustration of various conditions of rotational misalignment of the gears.

Referring now more in detail to the drawings, FIG. 1 illustrates a four-color multi-unit sheet fed press, in dicated generally by the reference numeral 10, and which includes individual printing units 12, 14, 16 and 18. As is conventional, a pile feeder, not shown, would be associated with the first printing unit 12 to feed sheets into that unit and a pile delivery, also not shown, would be associated with the unit 18 for receiving the printed sheets.

Each of the units 12, 14, 16 and 18 includes an appropriate inker mechanism and dampener mechanism, indicated generally by the reference numeral 20, together with a plate cylinder 22, blanket cylinder 24 and impression cylinder 26. A first transfer cylinder 28 they have a diameter twice the diameter of the impression cylinders. Each of the transfer cylinders includes two sets of grippers so that as a transfer cylinder is transferring a sheet to one cylinder it is receiving a sheet from another cylinder. The transfer cylinders 28 and 36 are conventional in construction and operation so further description of these transfer cylinders is believed unnecessary.

Referring now to the transfer cylinders 30, 32, 34, it will be noted that the two outer cylinders 30,34 are angularly arranged on opposite sides of the center cylinder 32 with a line interconnecting the centers of rotation of the three cylinders defining an angle which is other than l. As shown in FIG. 3, the cylinder 30 includes a pair of gaps 42,44 in which conventional grippers 41 are disposed. Similarly, the transfer cylinder 34 has a pair of gaps 38,40 in which grippers 39 are disposed. The center cylinder 32 is of the same construction as the other two cylinders, having gaps 46, 48 in which grippers 47 are disposed.

The grippers are supported for pivoting movement in a shaft, one such shaft being shown at 43 in FIG. 2. Appropriate spring means, not shown, act on the grippers to bias them to an open position. A cam follower 45, operatively associated with shaft 43, cooperates with a stationary cam 49 to move the grippers to a closed position. Although only one gripper cam and follower has been shown, it is to be understood that each of the sets of grippers is provided with a similar arrangement.

During normal operation of the press, a sheet is transferred from the transfer cylinder 30 to the transfer cylinder 32 when the gaps 42,48 on the two cylinders are aligned thereby accommodating the radially outward movement of the grippers 47,41. Similarly, a sheet is transferred from the cylinder 32 to the cylinder 34 when the gaps 38,46 are facing each other and the grippers 47,39 are interdigitated with the gaps accommodating the radially outward movement of the grippers. A sheet transferred to cylinders 30 and 34 has the freshly printed side facing the cylinder surface while the freshly printed side faces away from the surface of cylinder 32.

As is conventional, all of the cylinders in the press 10 are intergeared so that a single main drive motor 50 may be used to drive the first transfer cylinder 28 and, thereby, all of the other cylinders in the press. However, it is contemplated by this invention that the transfer cylinder 32 will be disconnected from the press gear drive train thereby dividing the press into two separate pairs of printing units so that make-ready operations can be performed on the two pairs individually and simultaneously. Disconnect of the transfer cylinder 32 is accomplished by displacing the gear associated with that cylinder out of mesh with the gears on the adjacent transfer cylinders 30,34 thereby interrupting the drive train. Thus, the intergeared relationship of the transfer cylinders is illustrated in FIG. 2 and comprises gears 52, 54, 56 secured to the cylinders 30, 32, 34, respectively. Each of the cylinders and their associated gears is supported for rotation between the side frames 58 with cylinder 32 and its associated gear 54 being supported on a shaft 60. The shaft 60 and the bearings supporting the shaft are slidably mounted in the side frames 58 so that the cylinder 32, including gripper cam follower 45, may be shifted axially to displace the gear 54 out of the plane of the two gears 52,56. Appropriate means are connected to the shaft 60 to shift the cylinder 32 which, as shown, comprises a hydraulic cylinder 61 and which is selectively actuated to shift the cylinder 32 to the right, as viewed in FIG. 2.

Upon actuation of the cylinder 61 to shift the gear 54 out of the plane of the gears 52,56, the drive through the press is interrupted thereby isolating units 16 and 18 from the units 12 and 14. To maintain operational alignment of cam follower 45 with the surface of cam 49, the nose portion 45a of the follower is axially elongated so that the nose portion shifts axially with cylinder 32 but remains in engagement with cam 49.

In accordance with this invention, means are provided for preventing both the disconnect and re-connect of the cylinder 32 except in a predetermined angular position together with means for maintaining the cylinder 32 in that predetermined angular position when disconnected so that the adjacent cylinders 30,34 may be individually rotated without the grippers on these cylinders interfering with the surface of the cylinder 32.

More specifically, the gear 52 is provided with a keeper ring 62 on the axial outer face thereof. Similarly, the gear 56 is provided with a keeper ring 64. Since the two rings 62,64 are similar in construction, only the ring 62 will be described in detail, it being understood that the same description applies to the ring 64. The construction of the keeper rings is best viewed in FIGS. 5, 6 and 7 and comprises a generally flat annular plate having a generally circular periphery 66 formed at a radius r,. The radius r is at least large enough to interfere with the mating gear 54. As shown, the radius r actually corresponds to the outside radius of the gear 52. It will be appreciated that with the keeper rings having this radius r,, the rings radially overlap the teeth on he gear 54 at the point of mesh between the gears 52, 54 and 56, and thereby preclude axial shifting of the gear 54.

To permit shifting of the gear 54 axially, notwithstanding the radially overlapping relationship between the keeper rings and the gear 54, there is provided on the periphery 66 of the keeper rings, a short arcuate interrupted segment 68. The arcuate segment 68 is formed on a radius r which is slightly greater than the radius of the addendum circle of the gear 54. When the gears 52,54 have been rotated to a position in which the meshing engagement between the two gears precisely corresponds with the arcuate interrupted segment 68, as shown in FIG. 7, the gear 54 may be shifted axially with the teeth of the gear passing through the space provided by segment 68. In precisely the same manner, the keeper ring 64 on the gear 56 cooperates with the gear 54.

To maintain the cylinder 32 and its gear 54 in an angularly fixed position after it has been disconnected,

there is provided an axially extending lug on the frame 58 with the lug being adapted to be received in a mating opening 71 in the axial end face of the gear 54. Lug 70 has a tapered nose portion which cooperates with a flared mouth in opening 71 to facilitate engagement of the lug in the mating opening. The axial extent of lug 70 is such that the lug enters the mating portion of opening 71 before the gears have moved completely out of mesh, thereby assuring that cylinder 32 does not rotate relative to the cylinders 30,34 during the disconnect operation.

The cylinder 32, in addition to having a pair of gripper gaps 46,48 has a pair of longitudinally extending machined flats 72,73 which form interrupted portions in the otherwise circular periphery of the cylinder. The angular spacing of the two flats 72,73 coincides with the angular spacing of the cylinders 30,34 about the cylinder 32 so that, upon disconnect, the flat 72 is facing the cylinder 34 while the flat 73 is facing the cylinder 30. In this angular position of the cylinder 32, independent rotation of the cylinders 30,34 may be accomplished with the flats 72,73 providing the required space into which the grippers 39,41 on the cylinders 34,30 may open as the cylinders are rotated. It will be appreciated that without the flats 72,73, the radial movement of the grippers 39,41 while the cylinder 32 is stationary would result in interference between the grippers and the periphery of the cylinder 32.

-It is to be noted that the flats 72,73 do not adversely affect the sheets carried by cylinder 32 since the printed side of the sheets is facing away from the surface of that cylinder so that the corners or edges of the flats contact only the back of the sheets.

The foregoing arrangement provides means for disengaging the cylinder 32 in a predetermined angular relationship and maintaining that angular position of the cylinder while permitting individual rotation of the adjacent cylinders. In addition, this invention contemplates means for re-connecting the cylinder 32 in exactly the same angular position relative to the cylinders 30,34 which it occupied prior to disengagement. Since the cylinder 32 remains stationary upon disconnect due to the engagement of the lug 70 in the aperture 71, the retiming of the transfer cylinders requires positioning of the cylinders 30,34 in the precise position which they occupied when the transfer cylinder 32 was disconnected. It will be recalled that the keeper rings 62,64 on the gears 52,56 prevented axial shifting of the cylinder 32 except in one predetermined angular position and these same keeper rings are the means by which the retiming of the cylinders is accomplished. Thus, it is necessary for the gears 52,56 to be rotated until the arcuate segments 68 on the keeper rings 62,64 are precisely aligned with the position at which the gear 54 will move back into mesh with the gears 52,56.

In addition to the keeper rings with the arcuate seg ments 68, additional means are provided to facilitate remeshing of the gears. Thus, referring to FIGS. 9 and 10, there are illustrated special camming gear teeth 80,81 and 82 which are carried on the gear 54.

Cooperating with these gear teeth are a pair of special gear teeth 84,86 on the keeper rings and which, in effect, provide an extension of the teeth on the gear 52. Each of the teeth 84,86 has a beveled or camming surface 85 on opposite sides thereof. The tooth 80 has similar beveled surfaces 87 while the'teeth 81,82 have a single beveled surface 89.

The manner in which these teeth cooperate to assure the proper remeshing of the gears is schematically illustrated in FIG. 12. Although only a pair of teeth are shown, the same principle applies to the other teeth. Thus, referring first to FIG. 12A, the teeth 84,81 are illustrated as being out of rotational alignment by less than three-fourths of a tooth but by at least one-half tooth. In this condition the blunt or flat forward end of the tooth 81 engages the equally blunt or flat end of the tooth 84 and blocks further axial movement of the gear 54 into the gear 52. In FIG. 128, the teeth are illustrated as being out of rotational alignment by less than one-half tooth and, in this condition, the beveled surface 89 on the tooth 81 engages the beveled surface 85 on the tooth 84. These cooperating surfaces allow the gear 54 to move into full meshing engagement with the gear 52 by the camming action of surfaces 85 and 89 which rotates gear 52 to a fully aligned position. FIG. 12C illustrates a condition wherein the teeth are out of rotational alignment by less than one full tooth but more than three-fourths of a tooth. In this condition, the forward end of the toothv 81 engages the beveled surface 85 on the tooth 84. However, the resulting camming action of the tooth 81 against the surface 85 causes rotation of the gear 52 in a direction which moves the gear 52 to a position where it is one full I tooth out of proper rotational alignment and gear 54 then engages the keeper ring, preventing further axial movement.

FIG. 9 illustrates the relationship of the gears 52,54 where the gears are out of the desired rotational alignment by one full tooth and, as is apparent from that Figure, the tooth 82 is blocked by the keeper ring at 62b thereby preventing remeshing of the gears. On the other hand, FIG. 10 illustrates a condition of the gears similar to that explained above in connection with FIG. 128 wherein the gears are out of rotational alignment by less than one-half tooth so that the beveled surfaces on the teeth of the gear 54 cooperate with the beveled surfaces on the teeth 84,86 to provide a camming action which rotates the gear 52 and its associated keeper plate to a position wherein the gear 54 may move fully into mesh with the gear 52.

' It is to be noted that in either the condition illustrated in FIG. 123 or FIG. 12C, there is a certain period of time required during which the camming action between the teeth occurs, either to align the teeth and establish a go condition or to rotate the gears to a no go condition where they are misaligned by one full tooth and the keeper plate blocks further axial movement. To provide the required time before a go or no go condition has been established, a pair of axial recesses 90,92 are formed in the axial face of the keeper rings on either side of teeth 84,86. These recesses enable the gear 54 to move axially into the teeth 84,86 a distance equal to the depth of the recesses before any engagement with the keeper rings occurs. If the gears are out of alignment by less than one-half tooth, as shown in FIG. [28 and FIG. 10, the recesses 90,92 enable the cooperating beveled surfaces on the teeth to cam the gears to the proper aligned position, thereby avoiding engagement of gear 54 with the keepers. On the other hand, if the gears are out by more than three-fourths of a tooth width, as shown FIG. 12C and FIG. 9, the recesses 90,92 enable the cooperating beveled surfaces on the teeth to cam the gears to a position where the gears are one full tooth out of alignment so that the blocking engagement illustrated in FIG. 9 occurs.

From the foregoing, it should be apparent that small rotational misalignments, up to one-half width, are automatically corrected and do not prevent re-engagement of the gears while misalignments of one-half tooth width or greater do prevent re-engagement.

It will be appreciated that although only one set of teeth 80, 81, 82 has been shown, the gear 54 includes a second set of teeth which cooperate with the gear 56 and the keeper ring 64 in precisely the same manner as described.

It is contemplated that the axial extent of lug will be such that it remains in the corresponding mating portion of opening 71 while the teeth on gear 54 are moving into the teeth 84,86 so that the cylinder 32 remains rotationally stationary until a clear go condition is established. It is to be noted that with the cylinder 32 secured against rotational movement, the camming action between the teeth described in connection with FIGS. 9, 10 and 12 results in rotation of gears 52,56 and, hence, each of the press units l2, l4, l6 and 18.

A suitable control circuit for the disconnect system will now be described, it being understood that control systems other than the one specifically disclosed may be used.

Each of the gears 52,56 is provided with a sensing block 94. Cooperating with the sensing blocks, and carried by the frames, are a pair of sensing probes 96 which comprise a part of a conventional proximity switch sensing head. The angular position of the sensing blocks 94 and the probes 96 is such that when the cylinders are in the position shown in FIG. 4, the proximity switch sensing mechanism will indicate that the two cylinders 30,34 and their associated keeper plates are in a disconnect or reconnect position. An appropriate circuit may be employed with the proximity switch sensing heads so that actuation of the hydraulic cylinder 61 is prevented except when the proximity switches indicate the cylinders are in the proper rotational position.

Assuming the proximity switches indicate the cylinders are in position for disconnect, an appropriate hydraulic circuit is then actuated to shift the cylinder 32 axially. One such circuit is shown in FIG. 11 and comprises an accumulator circuit having a threeposition solenoid actuated valve 100, an accumulator 102, a pressure switch 104 and a motor driven pump P. The valve has a pair of solenoids 106,108, solenoid 108 being operative to move cylinder 32 to an engaged position and solenoid 106 being operative to actuate the valve to move the cylinder to a disengaged position.

The circuit is actuated by the operator depressing a suitable control button to energize the appropriate solenoid 106,108 which will actuate the valve 100 and introduce hydraulic pressure to the hydraulic cylinder 61. If the gears 52, 54, 56 are properly positioned, the hydraulic cylinder will move the cylinder 32 and its gear 54 into or out of mesh with the gears 52,56. Appropriate limit switches LS-l and LS-2 are associated with the hydraulic cylinder 61 to signal when the cylinder has reached its extreme positions in either a connect or disconnect direction.

It is contemplated that hydraulic pressure will be maintained on the cylinder 61 both in the connect and the disconnect position to maintain cylinder 32 in the desired position.

In the event the gears are not rotationally aligned, as for example where the gears are out by one-half or more teeth as described above, the teeth on the gear 54 will interfere with the keeper rings 62,64 and, thereafter, further travel of the gear will be blocked. Upon such an occurrence, the operator will observe the blockage, release the control button and re-adjust the position of the gears.

To prevent any possibility of inadvertent movement of cylinder 32, as for example upon failure of hydraulic pressure on cylinder 61, the limit switches LS-l and LS-2 are adjusted to shut down the press upon any significant movement of cylinder 32 except during the disconnect or connect operation.

As a further safety precaution, it is desirable to provide in the press control circuit means which preclude jogging any of the press units during either the connect or disconnect sequence.

From the foregoing, it will be appreciated that the described arrangement not only provides a means for disconnecting units of a multi-unit press but also assures that during normal printing operations the driving forces throughout the entire press drive train are transmitted solely through meshing gear teeth. This is a highly important advantage in a multi-unit press where registry between units must be accurately maintained.

While transfer cylinders having generally circumferentially continuous surfaces have been disclosed, it is to be understood that the principles of the invention may be used with transfer cylinders having other configurations and arrangements. For example, the transfer cylinders may be of a skeletal construction in which event the skeletal construction of the cylinder would provide the relieved or interrupted portions necessary to accommodate the movement of the grippers when the units are individually rotated. Alternatively, the transfer cylinder 32 may be of a smaller diameter than cylinders 30,34 to provide the required clearance for the grippers.

While the invention has been described in connection with but a preferred embodiment, it is not intended that the disclosed embodiment or the terminology employed in describing it is to be limiting; rather, it is intended to be limited only by the scope of the appended claims.

Having thus described the invention, what is claimed 1. In a sheet fed printing press having a plurality of individual printing units and means for selectively drivingly interconnecting or disconnecting said units,

a train of drive gears for said press,

a pair of spaced vertical side frames,

a sheet transfer cylinder journaled on a horizontal axis in said side frames and having a gear at one end thereof constituting a portion of said gear train,

a pair of other cylinders angularly spaced around said transfer cylinder each having a gear at one end in mesh with the transfer cylinder gear,

at least a portion of the periphery defined by said transfer cylinder being spaced a substantial radial distance from the peripheries of said other cylinders to define clearances therebetween,

all of said cylinders having sets of interdigitating sheet grippers thereon for successively transferring sheets by means of said gripper from one printing unit to the next,

means for moving the transfer cylinder and its gear axially out of mesh with the gears for said other cylinders for disconnecting the printing units from each other,

mating means on said transfer cylinder gear and its adjacent side frame for retaining said transfer cylinder gear and transfer cylinder in a predetermined angular relationship relative to said other cylinders whereby the grippers of said other cylinders open into the clearances between the cylinders as said other cylinders are rotated relative to said transfer cylinder, and

means for diving each unit independently of the other while said gears are disengaged.

2. The printing press of claim 1 wherein the gears on said other cylinders and said transfer cylinder lie in the same plane when in mashing engagement.

3. The printing press or claim 1 wherein said meshing cylinder gears include means enabling engagement and disengagement of the teeth of the transfer cylinder gear with the cooperating teeth of the gears of said other cylinders in only one rotated position thereof.

4. The printing press of claim 3 wherein said latter mentioned means comprises keeper members on the gears of each of said other cylinders,

each of said keeper members having a periphery at a radius which is large enough to interfere with the teeth of its associated gear and extending around all but a short interrupted segment thereof.

5. The printing press of claim 4 wherein the short interrupted segment in each of said keeper members comprises an arcuate recess in the periphery thereof with said arcuate recess being formed on a radius of at least slightly greater than the radius of the addendum circle on the transfer cylinder gear.

6. The printing press of claim 5 and further including teeth means in said arcuate recess on each of said keeper members with said teeth means being adapted to engage and mesh with the teeth of said transfer cylinder gear.

7. The printing press of claim 6 wherein said teeth means on said keeper members have an axial extent greater than the axial extent of the adjacent portion of said keeper members whereby in the event of rotational misalignment between the gears during a re-connect operation said transfer cylinder gear moves into mesh with said teeth means before engaging said keeper member.

8. The printing press of claim 7 wherein said keeper members include axially extending recesses adjacent said teeth means.

9. The printing press of claim 4 wherein said keeper members and the transfer cylinder gears are operative to prevent engagement of said gear teeth in the event the gear teeth are out of rotational alignment by at least one-half gear tooth width, and further include means operative to cam the gear teeth into exact alignment in the event they are out of alignment less than one-half gear tooth width.

10. The printing press of claim 9 wherein said camming means includes camming surfaces on the teeth of at least one of the gears of each meshing pair of gears.

11. The printing press of claim 1 and further including sensing means for sensing the position of said pair of other cylinders relative to the transfer cylinder prior to axial movement of said transfer cylinder gear.

12. The printing press of claim 11 wherein said sensing means includes a pair of proximity switches mounted on said frame adjacent each of said pair of other cylinders and a sensing block rotatable with each of said other cylinders.

,13. The printing press of claim 1 wherein all of said cylinders are transfer cylinders between adjacent printing units and the middle transfer cylinder has its gear moved axially,

' said transfer cylinders being related to their printing units such that the outer two cylinders have the freshly printed side of each sheet facing the cylinder and the middle cylinder has the unprinted side of each sheet facing the cylinder during sheet transfer.

14. The printing press of claim 1 wherein said transfer cylinder includes shaft means supporting said sheet grippers and a cam follower operatively connected to said shaft means,

non-rotatable cam means in the path of movement of said cam follower for operating said shaft means to open and close said grippers to receive and transfer sheets as required during normal sheet transferring conditions, and

said cam follower including extension means extendin g transverse of said cam,

said transfer cylinder, transfer cylinder gear, grippers, shaft and cam follower all being mounted for axial movement as a unitary assembly upon operation of said disconnecting means with said extension means having an axial extent sufficient to maintain said extension means in contact with said cam as said transfer cylinder is shifted axially.

15. The printing press of claim 1 wherein said meshing cylinder gears include means enabling disengagement of the teeth of said transfer cylinder gear from the cooperating teeth of the gears of said cylinders in only one rotated position thereof.

16. The printing press of claim 1 wherein said mating means includes an axially extending lug on said side frame and an opening in said transfer cylinder gear in which said lug is received,

the axial extent of said lug being such that said lug is received in said opening before said transfer cylinder gear has moved fully out of mesh with said gears on said other cylinders.

17. In a sheet fed printing press having a plurality of individual printing units and means for selectively drivingly interconnecting or disconnecting said units,

a train of drive gears for said press,

a pair of spaced vertical side frames,

a sheet transfer cylinder joumaled on a horizontal axis in said side frames and having a gear at one end thereof constituting a portion of said gear train,

at least one other cylinder adjacent said transfer cylinder and having a gear at one end in mesh with the transfer cylinder gear,

said transfer cylinder having at least one interrupted portion in its periphery,

said cylinders having sets of interdigitating sheet grippers thereon for successively transferring sheets by means of said grippers from one cylinder to the next,

means for moving the transfer cylinder gear axially out of mesh from the gear of said other cylinder for disconnecting the printing units from each other,

mating means on said transfer cylinder gear and the adjacent side frame for locating said transfer cylinder gear and said transfer cylinder in a predetermined angular relationship relative to said other cylinder whereby the grippers on said other cylinder open into the space of the interrupted portion of the transfer cylinder periphery as said other cylinder is rotated relative to said transfer cylinder, and

means associated with said cylinders preventing disengagement of the teeth of the transfer cylinder gear from the cooperating teeth of the gear of said other cylinder except in one rotated position thereof.

18. The printing press of claim 17 wherein said transfer cylinder is shifted axially with said transfer cylinder gear.

19. The printing press of claim 17 wherein said means preventing disengagement comprises means carried by one of said gears and cooperating with the other of said gears to block axial movement of said transfer cylinder gear.

20. The printing press of claim 17 wherein said means for moving said transfer cylinder gear includes sensing means operatively associated therewith,

said sensing means being operative to sense axial movement of said gear means whereby any inadvertent movement of said gear means is sensed by aid sensing means.

21. in a multi-unit printing press having a pair of spaced vertical side frames,

a plurality of individual printing units arranged between said side frames,

said press including at least one sheet carrying cylinder having shaft means extending from either axial end thereof,

bearing means rotatably supporting said shaft means and said sheet carrying cylinder between said side frames,

a pair of other cylinders angularly spaced around said carrying cylinder and rotatably supported between said side frames,

a train of drive gears for said press,

motor means operatively connected to said drive gear train for operating said drive train to drive said press during printing operations,

said sheet carrying cylinder including a gear at one axial end thereof constituting a portion of said gear train,

said other cylinders each having a gear in mesh with said carrying cylinder gear, and

actuator means supported on said side frame and connected to said shaft means of said carrying cylinder,

said actuator means being operative to move said sheet carrying cylinder and its gear axially to interrupt the drive train through said cylinder gears and thereby disconnect the printing units from each other.

22. The press of claim 21 wherein said axial movement moves said sheet carrying cylinder gear out off meshing engagement with both of said other cylinder gears.

23. A method of disconnecting and individually operating the printing units of a multi-unit printing press of the type having a plurality of individual printing units supported between a pair of spaced side frames, at least one sheet transfer cylinder journaled on a horizontal axis between said side frames for transferring printing stock from one printing unit to the next and a pair of other cylinders angularly spaced around said transfer cylinder, a train of drive gears for said press with each of said cylinders having a gear at one end thereof constituting a portion of the drive train, all of said cylinders having sets of interdigitating sheet grippers thereon for successively transferring sheets by means of said grippers from one printing unit to the next, motor means for operating said drive train to drive all of the units of said press during the printing operation and auxiliary motor means associated with individual printing units to drive each unit individually, said method comprising the steps of:

shifting the transfer cylinder and its associated gear axially'out of mesh thereby to interrupt the drive train from one printing unit to the next, and selectively actuating the auxiliary 'motor means for individual printing units to drive the individual units as desired while maintaining the transfer cylinder in a position where the sheet grippers on each cylinder do not interfere with the adjacent cylinders. 

1. In a sheet fed printing press having a plurality of individual printing units and means for selectively drivingly interconnecting or disconnecting said units, a train of drive gears for said press, a pair of spaced vertical side frames, a sheet transfer cylinder journaled on a horizontal axis in said side frames and having a gear at one end thereof constituting a portion of said gear train, a pair of other cylinders angularly spaced around said transfer cylinder each having a gear at one end in mesh with the transfer cylinder gear, at least a portion of the periphery defined by said transfer cylinder being spaced a substantIal radial distance from the peripheries of said other cylinders to define clearances therebetween, all of said cylinders having sets of interdigitating sheet grippers thereon for successively transferring sheets by means of said gripper from one printing unit to the next, means for moving the transfer cylinder and its gear axially out of mesh with the gears for said other cylinders for disconnecting the printing units from each other, mating means on said transfer cylinder gear and its adjacent side frame for retaining said transfer cylinder gear and transfer cylinder in a predetermined angular relationship relative to said other cylinders whereby the grippers of said other cylinders open into the clearances between the cylinders as said other cylinders are rotated relative to said transfer cylinder, and means for diving each unit independently of the other while said gears are disengaged.
 2. The printing press of claim 1 wherein the gears on said other cylinders and said transfer cylinder lie in the same plane when in mashing engagement.
 3. The printing press or claim 1 wherein said meshing cylinder gears include means enabling engagement and disengagement of the teeth of the transfer cylinder gear with the cooperating teeth of the gears of said other cylinders in only one rotated position thereof.
 4. The printing press of claim 3 wherein said latter mentioned means comprises keeper members on the gears of each of said other cylinders, each of said keeper members having a periphery at a radius which is large enough to interfere with the teeth of its associated gear and extending around all but a short interrupted segment thereof.
 5. The printing press of claim 4 wherein the short interrupted segment in each of said keeper members comprises an arcuate recess in the periphery thereof with said arcuate recess being formed on a radius of at least slightly greater than the radius of the addendum circle on the transfer cylinder gear.
 6. The printing press of claim 5 and further including teeth means in said arcuate recess on each of said keeper members with said teeth means being adapted to engage and mesh with the teeth of said transfer cylinder gear.
 7. The printing press of claim 6 wherein said teeth means on said keeper members have an axial extent greater than the axial extent of the adjacent portion of said keeper members whereby in the event of rotational misalignment between the gears during a re-connect operation said transfer cylinder gear moves into mesh with said teeth means before engaging said keeper member.
 8. The printing press of claim 7 wherein said keeper members include axially extending recesses adjacent said teeth means.
 9. The printing press of claim 4 wherein said keeper members and the transfer cylinder gears are operative to prevent engagement of said gear teeth in the event the gear teeth are out of rotational alignment by at least one-half gear tooth width, and further include means operative to cam the gear teeth into exact alignment in the event they are out of alignment less than one-half gear tooth width.
 10. The printing press of claim 9 wherein said camming means includes camming surfaces on the teeth of at least one of the gears of each meshing pair of gears.
 11. The printing press of claim 1 and further including sensing means for sensing the position of said pair of other cylinders relative to the transfer cylinder prior to axial movement of said transfer cylinder gear.
 12. The printing press of claim 11 wherein said sensing means includes a pair of proximity switches mounted on said frame adjacent each of said pair of other cylinders and a sensing block rotatable with each of said other cylinders.
 13. The printing press of claim 1 wherein all of said cylinders are transfer cylinders between adjacent printing units and the middle transfer cylinder has its gear moved axially, said transfer cylinders being related to their printing units such that the outer two cylinders have the freshly printed side of each sheet facing the cylinder and the middle cylinder has the unprinted side of each sheet facing the cylinder during sheet transfer.
 14. The printing press of claim 1 wherein said transfer cylinder includes shaft means supporting said sheet grippers and a cam follower operatively connected to said shaft means, non-rotatable cam means in the path of movement of said cam follower for operating said shaft means to open and close said grippers to receive and transfer sheets as required during normal sheet transferring conditions, and said cam follower including extension means extending transverse of said cam, said transfer cylinder, transfer cylinder gear, grippers, shaft and cam follower all being mounted for axial movement as a unitary assembly upon operation of said disconnecting means with said extension means having an axial extent sufficient to maintain said extension means in contact with said cam as said transfer cylinder is shifted axially.
 15. The printing press of claim 1 wherein said meshing cylinder gears include means enabling disengagement of the teeth of said transfer cylinder gear from the cooperating teeth of the gears of said cylinders in only one rotated position thereof.
 16. The printing press of claim 1 wherein said mating means includes an axially extending lug on said side frame and an opening in said transfer cylinder gear in which said lug is received, the axial extent of said lug being such that said lug is received in said opening before said transfer cylinder gear has moved fully out of mesh with said gears on said other cylinders.
 17. In a sheet fed printing press having a plurality of individual printing units and means for selectively drivingly interconnecting or disconnecting said units, a train of drive gears for said press, a pair of spaced vertical side frames, a sheet transfer cylinder journaled on a horizontal axis in said side frames and having a gear at one end thereof constituting a portion of said gear train, at least one other cylinder adjacent said transfer cylinder and having a gear at one end in mesh with the transfer cylinder gear, said transfer cylinder having at least one interrupted portion in its periphery, said cylinders having sets of interdigitating sheet grippers thereon for successively transferring sheets by means of said grippers from one cylinder to the next, means for moving the transfer cylinder gear axially out of mesh from the gear of said other cylinder for disconnecting the printing units from each other, mating means on said transfer cylinder gear and the adjacent side frame for locating said transfer cylinder gear and said transfer cylinder in a predetermined angular relationship relative to said other cylinder whereby the grippers on said other cylinder open into the space of the interrupted portion of the transfer cylinder periphery as said other cylinder is rotated relative to said transfer cylinder, and means associated with said cylinders preventing disengagement of the teeth of the transfer cylinder gear from the cooperating teeth of the gear of said other cylinder except in one rotated position thereof.
 18. The printing press of claim 17 wherein said transfer cylinder is shifted axially with said transfer cylinder gear.
 19. The printing press of claim 17 wherein said means preventing disengagement comprises means carried by one of said gears and cooperating with the other of said gears to block axial movement of said transfer cylinder gear.
 20. The printing press of claim 17 wherein said means for moving said transfer cylinder gear includes sensing means operatively associated therewith, said sensing means being operative to sense axial movement of said gear means whereby any inadvertent movement of said gear means is sensed by aid sensing means.
 21. In a multi-unit printing press having a pair of spaced vertical side frames, a plurality of individual printing units arranged betweeN said side frames, said press including at least one sheet carrying cylinder having shaft means extending from either axial end thereof, bearing means rotatably supporting said shaft means and said sheet carrying cylinder between said side frames, a pair of other cylinders angularly spaced around said carrying cylinder and rotatably supported between said side frames, a train of drive gears for said press, motor means operatively connected to said drive gear train for operating said drive train to drive said press during printing operations, said sheet carrying cylinder including a gear at one axial end thereof constituting a portion of said gear train, said other cylinders each having a gear in mesh with said carrying cylinder gear, and actuator means supported on said side frame and connected to said shaft means of said carrying cylinder, said actuator means being operative to move said sheet carrying cylinder and its gear axially to interrupt the drive train through said cylinder gears and thereby disconnect the printing units from each other.
 22. The press of claim 21 wherein said axial movement moves said sheet carrying cylinder gear out off meshing engagement with both of said other cylinder gears.
 23. A method of disconnecting and individually operating the printing units of a multi-unit printing press of the type having a plurality of individual printing units supported between a pair of spaced side frames, at least one sheet transfer cylinder journaled on a horizontal axis between said side frames for transferring printing stock from one printing unit to the next and a pair of other cylinders angularly spaced around said transfer cylinder, a train of drive gears for said press with each of said cylinders having a gear at one end thereof constituting a portion of the drive train, all of said cylinders having sets of interdigitating sheet grippers thereon for successively transferring sheets by means of said grippers from one printing unit to the next, motor means for operating said drive train to drive all of the units of said press during the printing operation and auxiliary motor means associated with individual printing units to drive each unit individually, said method comprising the steps of: shifting the transfer cylinder and its associated gear axially out of mesh thereby to interrupt the drive train from one printing unit to the next, and selectively actuating the auxiliary motor means for individual printing units to drive the individual units as desired while maintaining the transfer cylinder in a position where the sheet grippers on each cylinder do not interfere with the adjacent cylinders. 